William Bartz 28, checking the feel of a vest as the fifty two recruits that started training this week are shown and fitted for body armor at the Denver Police Department's academy. Denver, CO. November 1, 2017 in Thornton, CO.

Two Colorado sheriff’s deputies died in separate shootings since Dec. 31 even though they were wearing body armor, prompting questions about whether the area’s law enforcement officers have enough protection from the powerful ammunition they face on the streets.

It’s a question that law enforcement agencies are asking themselves, too. The average ballistic vest issued to cops on the street is not strong enough to stop rounds fired by assault rifles.

“Those rounds are so high velocity, they go right through those vests,” said Westminster Police Department Cmdr. Gene Boespflug. “If it’s a solid-nosed bullet, it goes through a quarter inch of steel like butter.”

Even the strongest ballistic material is not fail-safe, experts said, because bullets can find their way into vulnerable places. Still, police deserve the best protection available to them, experts said.